Wearable devices have now gained increasingly popularity and has brought huge convenience to people's daily lives. In particular, smart watches have developed rapidly. In addition to the timekeeping function, smart watches can also be used to make phone calls and for fast payments.
However, the security of user information on smart watches has become increasingly important as the development continues. As such, how to ensure users a smooth operating experience while protecting the information security has become a subject of intense research. Current smart watches can only be triggered manually to enter the password-lock-screen mode. That is, after unclasped, to prevent others from entering the main interface to use the smart watch functions, the smart watch needs to be locked with a password. So, if the wearer forgets to lock the screen of the smart watch, which is then unfortunately stolen, then serious information security issues may arise, which may impact the security of bank accounts after the introduction of payment functions to the smart watch.